This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A278482 #34 Dec 23 2024 14:53:44
%S A278482 0,1,0,2,2,0,3,4,2,0,4,6,6,2,0,5,8,8,6,2,0,6,10,12,12,6,2,0,7,12,14,
%T A278482 14,12,6,2,0,8,14,18,18,18,12,6,2,0,9,16,20,24,24,18,12,6,2,0,10,18,
%U A278482 24,26,26,26,18,12,6,2,0,11,20,26,30,30,30,26,18,12,6,2,0,12,22,30,36,38,38,38,26,18,12,6,2,0
%N A278482 Square array A(n,k): A(0, n) = n; A(k, n) = A(k-1, floor(n*(k+1)/k)), for k >= 1, read by descending antidiagonals as A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), ...
%C A278482 Related to Flavius Josephus's sieve. See A278492 and the postings by _David W. Wilson_ et al. on SeqFan list, Nov 22 2016.
%H A278482 Antti Karttunen, <a href="/A278482/b278482.txt">Table of n, a(n) for n = 0..10439; the first 144 antidiagonals of the array</a>
%H A278482 D. Wilson et al., <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2016-November/thread.html">Interesting sequence</a>, SeqFan list, Nov. 2016
%H A278482 <a href="/index/Si#sieve">Index entries for sequences generated by sieves</a>
%H A278482 <a href="/index/J#Josephus">Index entries for sequences related to the Josephus Problem</a>
%F A278482 A(0, n) = n for n >= 0; A(k, n) = A(k - 1, [n*(k + 1)/k]) for k > 0 and n >= 0. Here [ ] stands for floor-function. From _David W. Wilson_'s posting to SeqFan list on 22 Nov 2016.
%e A278482 The top left corner of the array:
%e A278482 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
%e A278482 0, 2, 4, 6, 8, 10, 12, 14, 16, 18
%e A278482 0, 2, 6, 8, 12, 14, 18, 20, 24, 26
%e A278482 0, 2, 6, 12, 14, 18, 24, 26, 30, 36
%e A278482 0, 2, 6, 12, 18, 24, 26, 30, 38, 42
%e A278482 0, 2, 6, 12, 18, 26, 30, 38, 42, 48
%e A278482 0, 2, 6, 12, 18, 26, 38, 42, 48, 60
%e A278482 0, 2, 6, 12, 18, 26, 38, 48, 60, 62
%e A278482 0, 2, 6, 12, 18, 26, 38, 48, 62, 66
%e A278482 0, 2, 6, 12, 18, 26, 38, 48, 62, 78
%t A278482 t[k_, n_] := t[k - 1, Floor[n*(k + 1)/k]]; t[0, n_] = n; Table[t[k - 1, n - k + 1], {n, 0, 12}, {k, 1, n + 1}] // Flatten (* _Robert G. Wilson v_, Nov 23 2016 *)
%o A278482 (Scheme)
%o A278482 (define (A278482 n) (A278482bi (A002262 n) (A025581 n)))
%o A278482 (define (A278482bi row col) (if (zero? row) col (A278482bi (- row 1) (floor->exact (* col (/ 1 row) (+ 1 row))))))
%Y A278482 Transpose: A278483.
%Y A278482 Main diagonal: A278484.
%Y A278482 One less than A278492.
%K A278482 nonn,tabl
%O A278482 0,4
%A A278482 _Antti Karttunen_, Nov 23 2016 after _David W. Wilson_'s posting on SeqFan list Nov 22 2016